General Patton was an admirer of the M1 Garand (the greatest implement ever devised, he call it). The M35 2½ was what was needed to move those vast supplies when and where necessary. On the other hand, the M4 Sherman (in most of its variants, except for the British Firefly and quite possibly the Easy-Eights) was vastly inferior in combat capabilities when compared to most other medium tanks, and definitely all heavies. The M10 3-inch GMC, and the far better 76mm armed M18 Hellcat were fine vehicles but suffered heavily from the US Army Tank/Tank Destroyer doctrine, where only Tank Destroyers could engage tanks while tanks should avoid tank to tank combat, usually leading to disastrous consequences since the Germans failed to follow said doctrine. All this nonsense was finally scrapped and the M26 came to be.
So, let's head to the T34. Revolutionary is an understatement when applied to this magnificent piece of Soviet engineering (hold your shots, Christie fans!). Just to mention some of its characteristics we could say that it was fast, well armed, well protected, reliable, simple, sturdy, easy to build, easier to maintain, sporting an amazing ground pressure ratio, easy to man by crudely trained Siberian draftees, economical, and to top it all handsome as hell.
The first tank to have an all-aluminium diesel engine, which made it far less prone to burning at the first strike that the M4 Medium, Ronson, and provide a fantastic power to weight ratio (some 16 HP per tone in the early models). Wide tracks, coupled with large, rubber rimmed steel wheels and a fine (not spectacular) suspension, gave it formidable on road and cross-country mobility. The sloped armor was well thought through; it provided adequate protection without increasing the weight dramatically. The 76mm F34 gun was also adequate, although it lacked penetration and range later in the war. The latter 85mm D-5T and ZiS S53 were based on anti-aicraft guns, which gave them a higher muzzle velocity and a more tense trajectory. All in all, the beast was a thoroughbred since the start. Add to this that over 70.000 were built and you have a winner. A weapon that changed the way tanks were designed and made.
Was it all good in this KMDB piece of art? No, not at all. The original -76 had a crew of four (gunner/commander, loader, driver, radio operator/hull machine-gunner) which overloaded the commander, not giving him time to... well, command; the construction was sloppy at times, and the steel was not too good (the welding wasn't either!), and the ride was a bit rough for the crew. Things were vastly improved in the -85 series. Finally, and this is not the tank's fault, they were misused in the early stages of Barbarossa. Being thrown into the field piecemeal and almost randomly, instead than in large hordes and with some formation.
Nevertheless, the 34 was a huge shock to German troops and officialdom. The thing withstood all their efforts to be pierced by the standard infantry and most of the tank guns (save the well placed 50mm, or just about any hit by the 88). It was this tank which brought about the finest (though probably not the best all around) tank of WWII, The Pzkpfw V Panther.
On another note, you must remember that for the most part of the war, the eastern front was the war, whereas the other fronts were skirmishes until well into 1944.